6. The szlen Macro (string length)

• The szlen macro calculates the length of null-terminated string in memory:

  • szlen source

  where source is the beginning of a null-terminated string in memory.

      .DATA           ; Begin initialized data segment
          buffer      BYTE    12 DUP (?)
          ..
      .CODE           ; Code segment
          ..
          input   buffer, 12  ; Read zero to 10 ASCII characters
          szlen   buffer      ; Calculate user input length (result in EAX.)
          ..
  

• The length is returned in EAX.

• Flags affected: none.